An ice re-surfacing machine for skating rinks and the like has two basic parts. The first is the main wheeled body driven over the ice, usually on standard rubber tires. The body generally includes motive power, an operator's seat and controls, a collection system and storage bin for ice cuttings, water tanks for the ice-washing and ice-making process, and a hydraulic arms system for carrying and positioning the ice re-surfacing apparatus.
The second part is the apparatus that re-surfaces the ice in a single pass. This structure, which is towed over the ice by the main body, is generally referred to as the “conditioner,” but sometimes is called the “sled”. The conditioner, carried at the back of the main body on hydraulically activated arms, is essentially an open-bottomed steel box that allows the re-surfacing components access to the ice surface when lowered into operating position and pulled across the ice. A runner and side plate on each side, parallel to the direction of travel, supports the conditioner in operation and confines the ice chips and water used in re-surfacing.
The majority of imperfections created in the ice surface by ice-skating are limited to one to two millimeters of ice depth. The conditioner holds a large blade, usually steel, that shaves a very thin layer off the ice surface. Generally, the blade is attached to a supporting draw bar, which is mounted to the conditioner frame.
Ice cuttings generated by the shaving blade must be removed from the surface as the blade is pulled along. Mounted forward of and parallel to the blade is a screw conveyor, variously known as a “horizontal conveyor” or “horizontal auger” or “horizontal screw.” The horizontal conveyor comprises a cylindrical shaft onto which a helical flange, referred to as a “flight,” is wound around and attached, similarly to the thread on a wood screw. The helical flight converts the rotational spin of the shaft into linear motion parallel to the shaft.
In most ice-resurfacing machines, the horizontal conveyor is configured so that flights on the left side move ice shavings from the outside toward the center of the conveyor, and flights on the right side move ice shavings from the outside toward the center as well. In the center of the horizontal conveyor, flat plates mounted parallel to the rotational axis of the shaft, called “paddles”, connect to the left side and right side auger flights. The paddles are part of the “slinger”, which transfers ice shavings to a vertical conveyor. In operation, the blade shaves the ice, creating particles that build up in front of the blade and are caught in the flights of the horizontal conveyor. The horizontal conveyor's rotating flights move the ice particles to the center, where the slinger throws them onto the vertical conveyor.
The vertical conveyor is designed to accept the stream of ice cuttings thrown from the slinger of the horizontal conveyor and move them upward for placing into the ice cuttings storage tank in the main body. The vertical conveyor is also a screw type conveyor, similar in design and function to the horizontal conveyor. All of the helical flights are wound around the central shaft in the same direction, imparting a continuous upward movement of ice cuttings from the bottom of the conveyor to the top. At the top, slinger paddles sweep the cuttings into the storage tank. The vertical conveyor is encased in a close fitting metal tube running the length of the auger. A lower aperture, facing the slinger of the horizontal conveyor, receives ice cuttings from the slinger, whereby the cuttings begin ascending on the flights. An aperture at the top faces the ice cuttings storage tank. The vertical conveyor slinger paddles throw the ice cuttings into the tank.
Behind the blade and draw bar is a wash water system that discharges cold water through a manifold that sits parallel to the blade. The wash water system includes a rubber squeegee mounted on the bottom of the back wall of the conditioner and a suction pump with an intake that projects nearly to the surface along that back wall. In operation, cold water from a tank in the main body is discharged onto the ice surface just behind the blade assembly, and is constrained by the side runners and the squeegee as the machine moves forward. By regulating the flow of water and the suction of the collection pump, the operator maintains a wash water pool of constant size behind the blade assembly. This moving pool floats contaminants off the ice surface and floods any deep grooves and pits in the ice surface, then is collected and returned to the water tank.
The last part of the conditioner is the ice maker, mounted to the back wall of the conditioner. A discharge manifold sprays multiple small jets of hot water from a tank in the main body onto the outside back wall of the conditioner, where it forms a continuous sheet of water cascading down onto the ice across the conditioner's entire width. Finally a cloth water spreader, called a “mop”, evenly spreads and polishes the ice making water into a smooth surface.
Conventional ice re-surfacing machines shave the ice by forcing a blade forward through the ice as the machine travels forward. The cutting edge must part the ice on its cutting plane by brute pressure alone. Since ice is very hard, blades dull rapidly. Also, because the high cutting pressure strongly opposes the forward motion of the blade, strong propulsion and guiding forces are required to push the blade downward as well as forward. The present invention employs ultrasonic vibration of the blade to reduce the pressure required to force the blade through the ice and improve the quality of the ice cut.